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Molluscicidal tests indicated that type 44 was most active, achieving 100% kill
of Bulinus pfeifferi at 5 ppm for newly harvested berries and 7.5 ppm for
1-year-old and 10 ppm for 4-year-old ground berries (Table 2). At a concentration
of 10 ppm, types 3 and 17 killed all snails, but effectiveness decreased
considerably after storage.
The molluscicidal saponin yield of endod is about 25% of the weight of dry
ground berries. Thus, the amount of saponin that can be extracted from the
4th-year harvest is 688 kg! ha for type 44,463kg! ha for type 17, and 262 kg/ha
for type 3.
Field trials are now needed to establish molluscicidal efficacy and effect on
nontarget organisms in natural snail habitats in accordance with principles
and methods of field evaluation of plant molluscicides described by Sturrock
and Duncan (cited in Kloos and McCullough 1987). Assuming that a satisfactory
molluscicidal effect can be obtained at a concentration of endod of 20 ppm
Year
Table 1. Berry yields for endod types 3, 17, and 44 over 4 years.
Yield (kg dry weight/ha)
Type 3 Type 17 Type 44
1981-82 410 380 1 230
1982-83 850 1130 1 480
1983-84 1010 1300 2700
1984-85 1047 1850 2750
Total 3317 4 660 8160
Mean 829 1165 2040
Table 2. Molluscicidal potency (% mortality) of fresh, 1-year, and 4-year crude
powdered berries of endod types 3, 17, and 44 against B. pfeifferi.
Concentration (ppm)
10 7.5 5 4 Control
Fresh berries
Type3 100 60 0 0 0
Typel7 100 20 0 0 0
Iype44 100 100 100 30 0
1-year-old berries
Type3 100 60 0 0 0
Typel7 100 60 0 0 0
Type 44 100 100 60 20 0
4-year-old berries
Type3 100 0 0 0 0
Typel7 100 20 0 0 0
Type44 100 10 0 0 0
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